the surface characterization of a-axis euba/sub 2/cu/sub 3/o/sub 7-y/ (ebco) films sputtered onto srtio/sub 3/ (001) has been performed with a view to developing fabrication techniques for multilayer devices. scanning electron microscopy (sem) and atomic force microscopy (afm) studies indicate that a-axis ebco films have fairly smooth surfaces. in addition, an electron cyclotron resonance (ecr) ion beam is used for surface cleaning of a-axis ebco films surface analysis using x-ray photoelectron spectroscopy (xps), and reflection high-energy electron diffraction (rheed) show that the ecr oxygen ion beam treatment reduces the contaminated layer on a film surface and leaves a crystalline surface with an improved surface chemistry. ecr treatment at room temperature can result in reduced silver-contact resistivities in the 10/sup -8/-10/sup -7/ omega -cm/sup 2/ range. the surface processing using an ecr source would be useful in the fabrication of high-t/sub c/ multilayer devices